All handlers triggered by ib_drain_qp() should already see the
broken connection.

smb_direct_cm_handler() is called under a mutex of the rdma_cm,
we should make sure ib_drain_qp() and all rdma layer logic completes
and unlocks the mutex.

It means free_transport() will also already see the connection
as SMBDIRECT_SOCKET_DISCONNECTED, so we need to call
crdma_[un]lock_handler(sc->rdma.cm_id) around
ib_drain_qp(), rdma_destroy_qp(), ib_free_cq() and ib_dealloc_pd().

Otherwise we free resources while the ib_drain_qp() within
smb_direct_cm_handler() is still running.

We have to unlock before rdma_destroy_id() as it locks again.

Fixes: 141fa9824c0f ("ksmbd: call ib_drain_qp when disconnected")
Fixes: 4c564f03e23b ("smb: server: make use of common smbdirect_socket")
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

We now activate sc->recv_io.posted.refill_work and sc->idle.immediate_work
only after a successful negotiation, before sending the negotiation
response.

It means the queue_work(sc->workqueue, &sc->recv_io.posted.refill_work)
in put_recvmsg() of the negotiate request, is a no-op now.

It also means our explicit smb_direct_post_recv_credits() will
have queue_work(sc->workqueue, &sc->idle.immediate_work) as no-op.

This should make sure we don't have races and post any immediate
data_transfer message that tries to grant credits to the peer,
before we send the negotiation response, as that will grant
the initial credits to the peer.

Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers")
Fixes: 1cde0a74a7a8 ("smb: server: don't use delayed_work for post_recv_credits_work")
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

handle_response() dereferences the payload as a 4-byte handle without
verifying that the declared payload size is at least 4 bytes. A malformed
or truncated message from ksmbd.mountd can lead to a 4-byte read past the
declared payload size. Validate the size before dereferencing.

This is a minimal fix to guard the initial handle read.

Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers")
Cc: stable@vger.kernel.org
Reported-by: Qianchang Zhao <pioooooooooip@gmail.com>
Signed-off-by: Qianchang Zhao <pioooooooooip@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

We should wait for the rdma_cm to become SMBDIRECT_SOCKET_DISCONNECTED!

At least on the client side (with similar code)
wait_event_interruptible() often returns with -ERESTARTSYS instead of
waiting for SMBDIRECT_SOCKET_DISCONNECTED.
We should use wait_event() here too, which makes the code be identical
in client and server, which will help when moving to common functions.

Fixes: b31606097de8 ("smb: server: move smb_direct_disconnect_rdma_work() into free_transport()")
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

This introduces logic to prevent on overflow of
the send submission queue with ib_post_send() easier.

As we first get a local credit and then a remote credit
before we mark us as pending.

From reading the git history of the linux smbdirect
implementations in client and server) it was seen
that a peer granted more credits than we requested.
I guess that only happened because of bugs in our
implementation which was active as client and server.
I guess Windows won't do that.

So the local credits make sure we only use the amount
of credits we asked for.

Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers")
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

We have a list handling that is much easier to understand:

1. Before smb_direct_flush_send_list() is called all
   struct smbdirect_send_io messages are part of
   send_ctx->msg_list

2. Before smb_direct_flush_send_list() calls
   smb_direct_post_send() we remove the last
   element in send_ctx->msg_list and move all
   others into last->sibling_list. As only
   last has IB_SEND_SIGNALED and gets a completion
   vis send_done().

3. send_done() has an easy way to free all others
   in sendmsg->sibling_list (if there are any).
   And use list_for_each_entry_safe() instead of
   a complex custom logic.

This will help us to share send_done() in common
code soon, as it will work fine for the client too,
where last->sibling_list is currently always an empty list.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

There's no need to care about pending or credit counters when we
already disconnecting.

And all related wait_event conditions already check for broken
connections too.

This will simplify the code and makes the following changes simpler.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Make use of rdma_rw_mr_factor() to calculate the number of rw
credits and the number of pages per RDMA RW operation.

We get the same numbers for iWarp connections, tested
with siw.ko and irdma.ko (in iWarp mode).

siw:

CIFS: max_qp_rd_atom=128, max_fast_reg_page_list_len = 256
CIFS: max_sgl_rd=0, max_sge_rd=1
CIFS: responder_resources=32 max_frmr_depth=256 mr_io.type=0
CIFS: max_send_wr 384, device reporting max_cqe 3276800 max_qp_wr 32768
ksmbd: max_fast_reg_page_list_len = 256, max_sgl_rd=0, max_sge_rd=1
ksmbd: device reporting max_cqe 3276800 max_qp_wr 32768
ksmbd: Old sc->rw_io.credits: max = 9, num_pages = 256
ksmbd: New sc->rw_io.credits: max = 9, num_pages = 256, maxpages=2048
ksmbd: Info: rdma_send_wr 27 + max_send_wr 256 = 283

irdma (in iWarp mode):

CIFS: max_qp_rd_atom=127, max_fast_reg_page_list_len = 262144
CIFS: max_sgl_rd=0, max_sge_rd=13
CIFS: responder_resources=32 max_frmr_depth=2048 mr_io.type=0
CIFS: max_send_wr 384, device reporting max_cqe 1048574 max_qp_wr 4063
ksmbd: max_fast_reg_page_list_len = 262144, max_sgl_rd=0, max_sge_rd=13
ksmbd: device reporting max_cqe 1048574 max_qp_wr 4063
ksmbd: Old sc->rw_io.credits: max = 9, num_pages = 256
ksmbd: New sc->rw_io.credits: max = 9, num_pages = 256, maxpages=2048
ksmbd: rdma_send_wr 27 + max_send_wr 256 = 283

This means that we get the different correct numbers for ROCE,
tested with rdma_rxe.ko and irdma.ko (in RoCEv2 mode).

rxe:

CIFS: max_qp_rd_atom=128, max_fast_reg_page_list_len = 512
CIFS: max_sgl_rd=0, max_sge_rd=32
CIFS: responder_resources=32 max_frmr_depth=512 mr_io.type=0
CIFS: max_send_wr 384, device reporting max_cqe 32767 max_qp_wr 1048576
ksmbd: max_fast_reg_page_list_len = 512, max_sgl_rd=0, max_sge_rd=32
ksmbd: device reporting max_cqe 32767 max_qp_wr 1048576
ksmbd: Old sc->rw_io.credits: max = 9, num_pages = 256
ksmbd: New sc->rw_io.credits: max = 65, num_pages = 32, maxpages=2048
ksmbd: rdma_send_wr 65 + max_send_wr 256 = 321

irdma (in RoCEv2 mode):

CIFS: max_qp_rd_atom=127, max_fast_reg_page_list_len = 262144,
CIFS: max_sgl_rd=0, max_sge_rd=13
CIFS: responder_resources=32 max_frmr_depth=2048 mr_io.type=0
CIFS: max_send_wr 384, device reporting max_cqe 1048574 max_qp_wr 4063
ksmbd: max_fast_reg_page_list_len = 262144, max_sgl_rd=0, max_sge_rd=13
ksmbd: device reporting max_cqe 1048574 max_qp_wr 4063
ksmbd: Old sc->rw_io.credits: max = 9, num_pages = 256,
ksmbd: New sc->rw_io.credits: max = 159, num_pages = 13, maxpages=2048
ksmbd: rdma_send_wr 159 + max_send_wr 256 = 415

And rely on rdma_rw_init_qp() to setup ib_mr_pool_init() for
RW MRs. ib_mr_pool_destroy() will be called by rdma_rw_cleanup_mrs().

It seems the code was implemented before the rdma_rw_* layer
was fully established in the kernel.

While there also add additional space for ib_drain_qp().

This should make sure ib_post_send() will never fail
because the submission queue is full.

Fixes: ddbdc861e37c ("ksmbd: smbd: introduce read/write credits for RDMA read/write")
Fixes: 4c564f03e23b ("smb: server: make use of common smbdirect_socket")
Fixes: 177368b99243 ("smb: server: make use of common smbdirect_socket_parameters")
Fixes: 95475d8886bd ("smb: server: make use smbdirect_socket.rw_io.credits")
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull smb client fixes from Steve French:
 "smb client fixes, security and smbdirect improvements, and some minor cleanup:

   - Important OOB DFS fix

   - Fix various potential tcon refcount leaks

   - smbdirect (RDMA) fixes (following up from test event a few weeks
     ago):

      - Fixes to improve and simplify handling of memory lifetime of
        smbdirect_mr_io structures, when a connection gets disconnected

      - Make sure we really wait to reach SMBDIRECT_SOCKET_DISCONNECTED
        before destroying resources

      - Make sure the send/recv submission/completion queues are large
        enough to avoid ib_post_send() from failing under pressure

   - convert cifs.ko to use the recommended crypto libraries (instead of
     crypto_shash), this also can improve performance

   - Three small cleanup patches"

* tag '6.18-rc1-smb-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: (24 commits)
  smb: client: Consolidate cmac(aes) shash allocation
  smb: client: Remove obsolete crypto_shash allocations
  smb: client: Use HMAC-MD5 library for NTLMv2
  smb: client: Use MD5 library for SMB1 signature calculation
  smb: client: Use MD5 library for M-F symlink hashing
  smb: client: Use HMAC-SHA256 library for SMB2 signature calculation
  smb: client: Use HMAC-SHA256 library for key generation
  smb: client: Use SHA-512 library for SMB3.1.1 preauth hash
  cifs: parse_dfs_referrals: prevent oob on malformed input
  smb: client: Fix refcount leak for cifs_sb_tlink
  smb: client: let smbd_destroy() wait for SMBDIRECT_SOCKET_DISCONNECTED
  smb: move some duplicate definitions to common/cifsglob.h
  smb: client: let destroy_mr_list() keep smbdirect_mr_io memory if registered
  smb: client: let destroy_mr_list() call ib_dereg_mr() before ib_dma_unmap_sg()
  smb: client: call ib_dma_unmap_sg if mr->sgt.nents is not 0
  smb: client: improve logic in smbd_deregister_mr()
  smb: client: improve logic in smbd_register_mr()
  smb: client: improve logic in allocate_mr_list()
  smb: client: let destroy_mr_list() remove locked from the list
  smb: client: let destroy_mr_list() call list_del(&mr->list)
  ...

In order to maintain the code more easily, move duplicate definitions to
new common header file.

Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>